A buddy of mine at work helped me separate the piston from the cylinder. In a large vice we clamped a 3/4" piece of delrin (a type of plastic) to either side of the cylinder to form a good seal. We then drilled a hole through one of the delrin pieces and blew compressed air into the hole using a rubber-tipped air nozzle to seal to that hole. I am not sure if the higher air pressure available in the shop at my work or the better seal that motivated the piston out of the cylinder.... but either way, it is out and I am happy!

As expected, both the inner and outer 'O'-rings were shedding rubber pieces. I will need to do a bit of polishing to the sealing surfaces, but that should be a piece of cake.